What is bisclavert?

Bisclavert is a character in the medieval romance poem "Lanval" by Marie de France. He is a noble knight and a werewolf, cursed to take on wolf form during the full moon. Bisclavert is depicted as a sympathetic character who is betrayed by his wife and rescued by a fairy lover who helps him break the curse. The story is an example of the themes of betrayal, loyalty, and supernatural transformation that were popular in medieval literature.